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Spatiotemporal Microwave Imaging of Photo-carrier Dynamics in Monolayer Semiconductors

ORAL

Abstract

The spatiotemporal evolution of photo-generated charge carriers in two-dimensional transition-metal dichalcogenides (TMDs) plays a crucial role for their optoelectronic applications. A comprehensive understanding of such dynamics, however, remains a challenging task. Here, we report the simultaneous spatial and temporal photoconductivity imaging in WS2 monolayers by laser-illuminated microwave impedance microscopy. The diffusion length and carrier lifetime were directly measured. Time-resolved experiments indicate that the critical process for photo-carriers is the escape of holes from defect-induced trap states, which prolong the apparent lifetime of mobile electrons in the conduction band. This work provides fundamental knowledge on the defect-mediated spatiotemporal dynamics of charge carriers in 2D TMDs, paving the way for their applications in novel optoelectronic devices.

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Presenters

  • Zhaodong Chu

    University of Texas at Austin

Authors

  • Zhaodong Chu

    University of Texas at Austin

  • Chun Yuan Wang

    Physics, University of Texas at Austin, University of Texas at Austin

  • Jiamin Quan

    Physics, University of Texas at Austin, Department of Physics, The University of Texas at Austin, University of Texas at Austin, Department of Physics, Complex Quantum Systems, and Texas Materials Institutes, University of Texas at Austin

  • Chenhui Zhang

    King Abdullah University of Science and Technology, King Abdullah Univ of Sci & Tech (KAUST)

  • Chao Lei

    University of Texas at Austin

  • Ali Han

    King Abdullah University of Science and Technology

  • Xuejian Ma

    University of Texas at Austin

  • Hao-Ling Tang

    King Abdullah University of Science and Technology

  • Dishan Abeysinghe

    University of Texas at Austin

  • Matthew Staab

    University of Texas at Austin

  • Xixiang Zhang

    King Abdullah University of Science and Technology, King Abdullah Univ of Sci & Tech (KAUST)

  • Allan MacDonald

    University of Texas at Austin, Physics, University of Texas at Austin, Department of Physics, University of Texas at Austin, Department of Physics, The University of Texas at Austin

  • vincent Tung

    King Abdullah University of Science and Technology

  • Chih-Kang Shih

    University of Texas at Austin, Physics, University of Texas at Austin, Department of Physics, The University of Texas at Austin

  • Xiaoqin (Elaine) Li

    Physics, University of Texas at Austin, Department of Physics, The University of Texas at Austin, Department of Physics, University of Texas at Austin, University of Texas at Austin, Department of Physics, Complex Quantum Systems, and Texas Materials Institutes, University of Texas at Austin

  • Keji Lai

    University of Texas at Austin